Because a vertical weight of a rotunda weight adjustable boarding bridge is divided by an inner column and an outer column, only a vertical screw supports a weight of each of a rotunda, a fastened tunnel, and a boarding bridge.
Because the vertical screw may bear a wind pressure applied to a side surface of the rotunda and the boarding bridge, and a lateral weight caused by a movement and a stop of the boarding bridge, a size of the vertical screw may increase or a number of vertical screws may increase more than necessary.
Thus, development of a rotunda operable in a vertical direction that can endure the lateral weight is required.
The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention as defined in the claims is to be bound.